3D Collagen Orientation Study of the Human Cornea Using X-ray Diffraction and Femtosecond Laser Technology
3D Collagen Orientation Study of the Human Cornea Using X-ray Diffraction and Femtosecond Laser Technology
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DOI：
10.1167/iovs.09-3669
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发表时间：
2009-11-01
影响因子：
4.4
通讯作者：
Meek, Keith M.
中科院分区：
文献类型：
--
作者：
Abahussin, Mohammad;Hayes, Sally;Meek, Keith M.
目的。目的：研究纤维状胶原在整个角膜厚度不同深度的分布和优势取向。这些信息将形成角膜板层首选方向的全三维重建的基础。方法：使用飞秒激光技术将五个人的角膜中央区域分层为三个独立的层(前、中、后基质)，每一层都有预定的厚度。结果：人角膜中部和后部的胶原纤维沿上、下、鼻颞经方向呈择优的正交排列，板层数向外增多。然而，角膜前部(占总角膜厚度的33%)并没有表现出系统性的板层取向。结论：在人类角膜的后2/3，胶原主要分布在垂直和水平子午线(指向四大直肌)，而角膜前1/3的胶原更各向同性。中、后基质中胶原蛋白的垂直排列使其能够承受眼外肌的拉力，从而有助于角膜的应变分布，而角膜前部的各向同性排列在抵抗眼压的同时维持角膜的曲率，可能在角膜的生物力学中起重要作用。(投资眼科VS科学。2009年；51595164)doi：10.1167/iovs.093669
PURPOSE. To study the distribution and predominant orientations of fibrillar collagen at different depths throughout the entire thickness of the human cornea. This information will form the basis of a full three-dimensional reconstruction of the preferred orientations of corneal lamellae.METHODS. Femtosecond laser technology was used to delaminate the central zones of five human corneas into three separate layers (anterior, mid, and posterior stroma), each with predetermined thicknesses. Wide-angle x-ray diffraction was used to study the gross collagen fibril orientation and distribution within each layer.RESULTS. The middle and posterior parts of the human cornea demonstrated a preferential orthogonal arrangement of collagen fibrils, directed along the superior-inferior and nasaltemporal meridians, with an increase in the number of lamellae toward the periphery. However, the anterior cornea (33% of total corneal thickness) showed no systematic preferred lamellar orientation.CONCLUSIONS. In the posterior two thirds of the human cornea, collagen lies predominantly in the vertical and horizontal meridians (directed toward the four major rectus muscles), whereas collagen in the anterior third of the cornea is more isotropic. The predominantly orthogonal arrangement of collagen in the mid and posterior stroma may help to distribute strain in the cornea by allowing it to withstand the pull of the extraocular muscles, whereas the more isotropic arrangement in the anterior cornea may play an important role in the biomechanics of the cornea by resisting intraocular pressure while at the same time maintaining corneal curvature. (Invest Ophthalmol Vis Sci. 2009;50:5159-5164) DOI:10.1167/iovs.093669